The Groundhog Game
by Anonymonimus
Summary: Sans was a peculiar monster. He always seemed and acted like he was content with life. However, with every reset, you had come to see that reality was quite the opposite. It took you a while to figure out it was because he was missing someone more than it was the resets bothering him. It took you even longer to learn who. But once you did, you found a way he could be saved.
1. One Year Later

It had been a little over a year since the last reset and you felt no need to change that either. You created a new safe point for yourself beyond the Underground this time, but never had any intention of ever using it. You had been doing good for a kid – better than most adults, in fact. When you emerged with the monsters from beneath Mt. Ebott, you protected them and took them under your wing. It was your job as ambassador, but you also loved them and would have done it regardless. You made a place for them in your world and once you had gotten your kind to accept them the way you did, you focused on the ones closest to you.

Your goal was first and foremost to make everyone happy. You never wanted to hurt anyone. So when you got the chance, you made sure to fill your closest friends with joy by helping them accomplish their dreams. You had Papyrus pass a driving exam and, once he did, you gave him a car. You introduced Undyne to the MMA and she became a world renowned champion fighter. You sent Mettaton to a TV interview you were meant to attend and skyrocketed him to fame – he now possessed one of the biggest fan bases you'd ever seen and it was a little terrifying. You brought Alphys with you to a UN summit to legitimise King Asgore as a monarch and leader of Monster kind; by doing so, you made her intellect as a royal scientist known to the world and she was recruited by multiple prestigious scientific organisations and universities. As wonderful as it was, Alphys had the worst time of her life choosing between all of them. Finally, you used the money you acquired from working so diligently in the past year to help Toriel open a school, which you also decided to attend.

Everyone was truly happy…well, almost everyone.

Today was the Monster holiday known as: 'Peace Day' – a name obviously chosen by Asgore. It was the day, a year ago, you had legitimised his royal status and bestowed rights to Monsters equal to those of Humans upon them. To celebrate, all the monsters who still remained in the surroundings of Mt. Ebott came to your and Toriel's home for a big party. A couple of human diplomats and other important personalities also decided to attend along with journalists and paparazzi to immortalise this important moment. You stood on one of the balconies overlooking the ballroom of your immense home and smiled as you noticed how humans and monsters intermingled with one another easily. It was like there had never been a time where the two species hadn't coexisted.

You looked down to the entrance and saw Mettaton chatting up journalists and posing for their photographers. You expected no less of him. He was probably promoting the film he would be starring in soon. You looked away, turning your gaze to Asgore who seemed to be hounded by children and diplomats. He was evidently flustered by his conundrum, but couldn't find it in himself to turn anyone away. As such, he discussed international affairs with children hanging off his every limb. You chuckled before finding the rest of your friends huddled around the buffet table. Alphys seemed utterly embarrassed as she watched her girlfriend shovel food in her mouth as quickly as possible against Papyrus in a sort of competition. Sans loomed next to her with his typical grin on her face. As funny as the sight was, the smile on your lips faded as your gaze lingered on Sans.

Sans was a peculiar monster. He always seemed and acted like he was content with life. However, with every reset, you had come to see that reality was quite the opposite. When he thought no one was looking, the smaller skeleton would stare off into the distance with a forlorn expression. The pain and anguish he kept hidden would flood his features and his eyes would dim. It took you a while to figure out it was because he was missing someone more than it was the resets bothering him. It took you even longer to learn who. But once you did, you found a way he could be saved – or rather, a way for _Sans_ to save him.

That was part of the game.

All that was left was to find a way to corner Sans. You had to be direct but convincing. The idea you planned to present to him might not seem like the best one at first glance, but it was the only way. You continued watching the smaller skeleton as he moved to rub soothing circles in a disappointed Papyrus's back while Undyne threw her arms up victoriously and cackled noisily. It would seem that she had won their competition. Alphys looked as embarrassed as ever and was desperately trying to get them to shuffle along.

"Frisk." You heard Toriel utter softly from behind you. You turned to face her and as you did so, she placed a comforting hand on your shoulder. She looked down at you with loving eyes and offered you a smile. "What are you still doing up here? You should be celebrating down there."

You glanced back at the party below and nodded. She was right; though you would have much preferred to simply look over everyone because you would get to see them happy. Another time, you supposed. You allowed Toriel to guide you towards the stairs and you leaned into her warm, comforting touch. You would likely be spending most of the party by her side.

Once you arrived at the bottom of the stairs, you were immediately noticed by all the neighbouring monsters. They beamed at your presence and huddled around you, shouting and cheering 'happy peace day!' You simply smiled as you weren't much for words. The gesture seemed to get your message across just fine all the same. Toriel lead you past them and the others who flocked to you, bidding you the same sentiment. Eventually, you reached the cake she had confectioned for this event. You were expected to give a speech of the sort before cutting the first piece. There was even a little podium for you to step on.

So step on it you did. You could now just barely see above the heads of the hundreds of Monsters and Humans flooding your home. They all looked eager to see what you had to say. You cleared your throat and straightened your clothes. You looked around the room, meeting everyone's gaze for at least a brief second. Then, you took a deep breath and paused dramatically. You concluded your speech with a double thumbs up that had all the Monsters cheering and clapping. Your kin looked absolutely confused but nevertheless clapped as they wondered if you were going to give a speech or if that was it.

You really weren't much for words.

From that moment on, the party livened up further. It became louder and more people seemed to join. You remained by Toriel's side, content to watch her chat with others and have a good time. Your eyes drifted every now and again to the sea of folk surrounding you until you found Sans somewhere in the chaos. Your gaze lingered on him and you waited to see if he would make a move to leave. It took him a while to declare he wanted some fresh air and, when he did, you followed. Gently tugging on Toriel's sleeve, you pointed outside to tell her where you were going before actually leaving. The last thing you wanted was for her to worry.

Now the game was beginning.

You weaved through the thick crowd of monsters and humans, finally reaching the glass door left ajar. You stepped into your backyard, finding Sans leaning against the fence of your porch. His eyes were closed and he seemed to be taking in the fresh air like he said he would. Despite not having reacted in the slightest, you knew he knew you were there. Still, you let him take his time to acknowledge you. Time wasn't an issue in this game, it was endurance.

"you've been watching me a lot tonight, kid." He finally said, opening his eyes and glancing in your direction. "something you want to tell me?"

How to start? Where to start? From the beginning, you supposed.

"You're sad." You said quietly. Your voice was raspy from being so unused. If only you could convey everything you ever wanted to say through a handful of looks and gestures, then you wouldn't have to use it at all. Sadly, it wasn't the case. "You pretend you're happy, but you're sad."

Being outed seemed to tear away at the façade Sans attempted to uphold day in and day out. You saw the sadness he normally tried to keep to himself twinkle in his eyes. "yeah?"

"Is it because of him?" You asked and even though you haven't yet said his name, Sans tensed visibly. "Gaster?"

Incredulousness overtook the smaller skeleton's features. It was like he couldn't believe the name left your lips, but it did and he didn't know how to feel about it. His mouth twitched and moved into different shapes, wanting to ask everything at the same time. Sans struggled to pick his first question. "how?" He eventually asked.

"I met him once." You told him and you didn't miss the sharp breath Sans took in. The confession peeled his mask further away and you could now see how broken he really was. "It was an accident, I think. First, I met a monster – grey, lifeless – who talked about him. About how he fell. Then I found a door that shouldn't have been where it was. He was inside. I don't think he thought I could see him until I reached to touch him."

"what did he do?" Sans asked, his voice strained from a flurry of emotions.

"He disappeared." You answered. You met more grey, lifeless monsters who talked about him afterwards, but you kept that to yourself. It wasn't important. Instead, you opted to ask: "Who was he to you?"

For all the grey monsters had told you, you knew very little about Gaster. He was the royal scientist before Alphys. He built the Core which powered all of the Underground and, one day, he fell in. Somehow, this resulted in no one remembering him – _almost_ no one. Sans remembered; how you figured that one out, you absolutely couldn't remember nor fathom. But Sans remembered and that was all that mattered.

"he was my best friend." Sans answered and the forlorn expression he typically wore when he thought no one was paying attention overtook him. He wore a bitter smile and his gaze was dazed, focusing on nothing as he probably fell into the depths of his memories.

"How did he fall?" You asked.

"he was trying to bring down the barrier." Sans explained, scrunching his face in thought. It seemed like he was having a hard time piecing the memories together. "he built a machine powered by the core and when he activated it, he fell." You frowned. Sans laughed, evidently reading your thoughts just from your expression. "that was vague, i know. truth is, i don't remember it very well." His smile became bitter, "my memories of him change with every reset. sometimes, he's just a feeling of something missing – i can't remember his face nor who he was to me, but the pain of his absence is still there. sometimes i can remember everything perfectly, so much so i could draw a detailed portrait of him if i was remotely artistic. most of the time, i remember bits and pieces."

"What do you remember now?" You asked. It was vital to the game.

"he was my best friend." Sans repeated with a shrug, "i knew him all my life. we worked together as scientists; i might have been his assistant or just his confidant. i was there when he fell and i tried to catch him, but i couldn't. that's it."

You nodded. He made no mention of remembering his facial features – either because he couldn't or he only remembered little. However, you were certain that once he saw him, he would be able to identify him. Regardless, whether he recognised him the first time or not wouldn't be an issue. Time wasn't the issue. Now that you had gotten the conversation where you wanted, you needed to branch off into the game and make Sans a willing participant.

"I want everyone to be happy. I want _you_ to be happy." You told him. Your heart was beating just a little faster in your chest. It would be fine. It would work. "I know how to save him."

Deafening silence washed over the both of you. Sans stared at you in bewilderment, not quite grasping what you were offering him. He had tried to save Gaster before, if that machine in his hidden lab was anything to go by, but had failed. Perhaps he had given up on the prospect and had accepted that his goal was just unattainable. The thoughts that must have been rushing through his head…

"okay." He answered quietly. You weren't quite sure what he meant by it. "let's do it."

Now it was your turn to be shocked. Sans asked questions. He was smart. He didn't get involved in things without knowing the full scope. He was currently being reckless. That was very much unlike him. "You're not going to ask me questions…?" You asked him because you were so taken off guard by his compliance.

"i trust you, Frisk." Sans stated and he sounded so honest it made you feel guilty. A part of you struggled to understand why he would trust you. Though he could never remember the true resets, Sans knew what you had done time and time again. He knew about the blood – nay, _dust_ staining your hands and clothes. You were different now, but did that matter especially when what you were about to do was taken into consideration?

"Follow me." You simply replied.

You walked down the short steps of your back porch with Sans hot on your tail. He followed you quietly as you began circling the house looking for Him. He had told you He would be skulking about; if not being an annoyance on the inside, than watching the others from the outside. You spent a good few minutes just searching for Him and you could feel Sans starting to wonder why it was taking so long. Just when he was about to bring it up, you noticed Him in the bushes. His white little tail stuck out from the green leafs for a flash, but that was all it took. You wandered to His hiding spot and parted the leafs. Sans seemed rather surprised to see Him.

"a dog?" He asked quizzically.

And yes. At first sight, He appeared to be nothing more than an adorable, white pooch – and, in a way, He was. However, He was also so much more. You had a hard time finding a good word to describe Him. He was just so complicated to define as one thing, but He also barely fit into any label. Was He a dog? Sometimes. Was He a monster? Maybe. Was He a human? Depended on the day.

"Ah, Frisk!" He said, attempting to cover the slice of chocolate cake He had undoubtedly stolen from the party. You reached past Him and took it. Chocolate wasn't good for dogs. "Oh come on!" He whined, "Just a little slice won't hurt!" You stared at Him dead in the eyes as you swallowed his piece in one bite. "No! You're so cruel!" He howled.

"what's going on?" Sans asked.

"Frisk ate my cake, that's what's going on." The Dog pouted.

"why did you bring me here?" Sans asked, looking at you for answers.

You elected to ignore him. "He's willing." You told the Dog.

"Is he now?" The Dog responded musingly. "I imagined he would have less obvious questions to ask."

"He didn't ask any." You said, and perhaps Sans regretted trusting you so much now. It didn't matter. It was too late.

"Curious." The Dog nodded and brought His paw to His chin – a very human gesture you've been privy to multiple times. It was what made you doubt he was all monster to begin with. His beady eyes fell upon Sans. "How much does Gaster mean to you for you to be so reckless?"

You glanced at Sans as well. He probably had a few of his queries answered with that simple question. They were in front of a bush talking to a little white dog because it was the first step in saving Gaster. But now that you considered it further, he probably had more questions now than he did before. It didn't matter. They would eventually all be answered. For the moment, you were equally curious. What was it about Gaster that pushed Sans to be unnaturally thoughtless?

"you're going to help us save Gaster?" Sans asked.

"No." The Dog answered with an amused laugh, "I'm going to _allow_ you to save him."

Sans seemed perplexed by the answer. "who are you?"

"Today, I'm a little dog." He answered, "Maybe tomorrow too. And the day after. I like being a dog."

"I think…" You started off slowly, trying to find the right words to describe Him. "I think He's some sort of God." The Dog exploded into a loud fit of laughter at that, but you continued all the same. "He's as strong as one and He's capable of unnatural feats. The rules of physics and all that we know don't seem to apply to Him."

"When you put it like that," The Dog said, "Maybe being described as some sort of God isn't entirely crazy."

"this is…" Sans started but trailed off. He was evidently flustered by the turn of events and didn't know how to react to it. You didn't blame him. "i really wasn't expecting this…"

"How could you?" The Dog snorted, "It's not like it was predictable. Regardless!" He turned towards you with a twinkle in his eyes, "The Game is afoot, Frisk! Shall we be on our way?"

You nodded and, once you did, you were swept off your feet. For a second, it felt like you were falling. Whether you had or hadn't, you would never know. You were surrounded in a darkness that had crept up on you unexpectedly, but it wasn't frightening – it was familiar. You had been in that darkness so many times before and, when you looked up, you found the familiar orange letters floating above your head. There was a sort of sense of nostalgia rushing through your veins after being absent for so long. A part of you missed the feeling of re-experiencing one of the most unique moments of your life and tweaking little aspects of it. You would never get tired of meeting your friends for the first time. However, you eventually had to move on and so you did.

"where…where are we?" Sans asked in awe, glancing up at the orange letters. You had almost forgotten he was there what with being so used to solitude.

"The Loading Screen." You answered. "It's where you can access the save file—"

"and the reset button." Sans finished. He caught on fairly quickly. He was smart. Would he want to play the game when he knew what it was? "is this how you manipulated the timeline?"

You nodded in affirmation.

"Brings back memories, doesn't it?" The Dog asked, drawing yours and Sans's attention to Him. "However, this isn't Frisk's Loading Screen; it's mine." He informed further, "I have far more save files."

Suddenly, the orange letters above your head were just off to your left. It appeared that you were shifted swiftly to a higher level or that the words were brought down to yours. In the end, it didn't matter. You watched the Dog give a brief flick towards His save files and watched as hundreds of them zoomed past your eyes. You couldn't understand how He could make sense of them when they were all labelled by numbers so you chalked it off to his God-like powers.

"before we take this any further." Sans said, "can someone please explain to me what's going on?"

"I was wondering when you would demand answers." The Dog chuckled, "What exactly would you like to know?"

"for starters, what's this 'game' you mentioned?" Sans asked.

"When Frisk came to me for help, I made a proposition to them." The Dog explained, "I would give you the opportunity to save W.D. Gaster and we would watch to see if you succeeded or failed. Your failure means my victory and your success means my loss." Sans frowned at that and was immediately on his guard; needlessly so. "Don't get any ideas, here! I'm not the antagonist of this story! If I'm a God, I'm a careless, absent God. I'm only doing this just because."

"what happens to Frisk if i can't save him?" Sans asked, and you felt touched that he was still concerned for you.

"Don't worry about it." The Dog replied.

Sans obviously wasn't satisfied with the answer, but he understood he wasn't about to get anything better. Instead, he opted to keep going. He turned to you; "how did you come across Him?"

"It's complicated. I've met him a lot of times." You answered. "I didn't know what he was until I beat the Credits. I was able to open that door – the one in the caves just outside of Snowdin. I found him inside and learned what exactly he was."

"why did you make such a potentially dangerous deal with Him?" He asked, but sounded reproachful. It seemed that Sans didn't approve of your decision to place yourself in a bet with a God-like creature. If He was anyone else, his concern would be justified.

"Don't worry about it." You simply replied, and the Dog approved.

"so what now?" Sans sighed and turned to the Dog as well. "what's this game i'll be starring in?"

"I'm glad you asked!" The Dog barked excitedly, wagging His tail madly, "It's the Groundhog Game! I'm going to send you back to the three days before Gaster erases himself from the timeline. Your job will be to stop him from doing whatever it was that went terribly wrong and effectively save him. You can have as many tries as you like and you can tell him whatever you want – even the truth. If you think he'll believe a little white dog and a human child are watching you; tell him! Whatever you do, you just have to end up saving him. If, by the end of the time I've given you, you haven't managed to save him – _don't worry about it!_ You can try again! You can try as many times as you like! You can even stay trapped in an eternal loop of those three days – though I already know you don't want to. The game ends when you've either won or given up."

You watched Sans carefully throughout the explanation of the game. You were concerned and rightfully so. The moment the Dog mentioned he could reset as many times as he liked, something changed in him. He seemed more fragile, which was very bad for you. You could already see him begin to cave under the weight of resets and now you weren't so sure accepting to this was a good idea even if it was the only option for Gaster. You knew how much Sans hated the resets and how they affected him. They made him depressed and apathetic. They made him sleep and sleep, because there seemed to be no point to his actions with them around.

The resets were the worst things Sans could imagine. You wanted Sans to be happy. So why was it that you decided he should suffer through them and witness the death of his best friend time and time again until he figured out a way to save him? A part of Chara must have still been lingering inside of you. They would never truly leave you. You were bonded. _Partners._ But you pushed the thought aside. Sure, Sans would suffer, though only for a little while in the grand scheme. If he succeeded like you hoped he would, he would finally be happy. Everyone would truly be happy.

You never wanted to hurt anyone.

"now i understand…" Sans huffed bitterly and glanced at you, "i get why you kept looking at me like you had hurt me."

You bit your lip and looked away guiltily. What were you supposed to say to that?

"Despite you being here," The Dog said, "You can still refuse to be a part of this game."

"what happens to Frisk if i do?" He asked.

"Nothing. The game is annulled." The Dog answered, "Our little bet is also annulled and Frisk finds themself in a situation to convince me through some other means to save Gaster."

You're both impressed and angered by the way He decided to word his sentences. You wondered if the Dog realised He had essentially manipulated Sans into agreeing to their game. If He did, and He probably did, He was a cruel God. Crueller than you yourself – and that was saying a lot. Regardless, you watched Sans lament his predicament and weigh his options. You felt terrible because you were terrible. What kind of friend would do that, even with the best intentions? You should have probably looked for a better way but it was too late now.

"fine." Sans decided resolutely. "i'll do it. for Gaster."

"Excellent!" The Dog yipped and hopped around.

He turned towards the list of save files and began scrolling through them. They flew by in front of your eyes too fast for you to keep track. Soon, it was nothing more than a blur of orange until, abruptly, it stopped. Only one file was displayed in the darkness: 19950714. You heard Sans suck in a shaky breath.

"I believe in you." You muttered to him, though it probably meant nothing. Sans hardly acknowledged that you had said anything.

"You'll have all the memories you harbour now." The Dog said, glancing over his shoulder. "Any questions?" Sans shook his head. "Off you go."

And the next thing you knew, the small skeleton was gone. You were left alone in the darkness with the Dog. You felt a pit in your stomach. You had made a mistake. Red flags had been raised and alarm bells were going off; but it was too late. You felt a glare baring into your back, but you couldn't imagine why as you were shrouded in darkness. It was just you and the Dog and the latter was looking at you with innocent eyes, not reproach nor hatred. It was most likely just your imagination, then.

"He's going to break, I think." The Dog mused and He was probably right. "How many resets, do you reckon?"


	2. Days of Old

The first thing he saw was a massive clock established in the middle of a large street. It was sculpted from sand coloured bricks and bore intricate carvings of Monster's most notable historical characters. The clock itself rested in a home on top of a cylindrical pillar with a thin but clean layer of glass shielding it. Sans watched as the handles made of gold strands woven together moved to mark three in the afternoon. A gong went off in the base of the structure, resounding deafeningly in his head three times before stopping. Once it was done, the small skeleton blinked dumbly at his surroundings.

Where he was once in a place shrouded in darkness, he was now located in an unfamiliar town – no, _city_. The streets were of cobble stones, twisting and turning beyond the giant clock. It outlined the surrounding buildings that were so tall they nearly scrapped the top of the cavern ceiling. There was little space in between the edifices, but glimpses of blue tiles could be spotted in between if Sans tilted his head just right. The colour was in stark contrast with the sandy tones of his surroundings and he found himself staring at it for quite some time in a state of incredulity. He knew those tiles – to what they belonged to – but he couldn't quite believe it because it didn't make sense.

Before he could think on it any further, Sans felt something tugging at his sleeve. He glanced down finding bony fingers gripping his white sleeve and, when he looked up to see who they belonged to, he was surprised to find Papyrus standing before him. His brother looked almost identical to how he remembered him; if a bit younger. Aside from that, the only off putting thing about him were the clothes he wore. They were…normal. He wore a brown jacket which he kept buttoned shut, his familiar orange scarf, and a pair of dark gray pants with some matching boots. There were no vibrant colours; nothing loud or flamboyant to indicate what kind of person Papyrus truly was.

"Pa…pyrus…" Sans muttered slowly. He still couldn't quite believe that the skeleton touching him was his brother. He seemed the same with his concerned expression and all, but he also looked significantly different. Everything around him felt that way, the more he considered it: familiarity cloaked in the foreign. "why aren't we in Snowdin?"

Though the question was mostly to himself, Papyrus took it as addressed to him. He frowned further, his concern growing seemingly because of the inquiry. Sans couldn't understand why; it was legitimate. After all, hadn't they lived in Snowdin their whole lives?

"Why _would_ we be in Snowdin?" Papyrus returned. "We have no reason to be there."

Sans stared at him, dumfounded. He had been so certain their only home had ever been in Snowdin, but Papyrus's tone suggested otherwise. It would seem that his memory wasn't as accurate nor as reliable as he once thought it to be. If not there; where _was_ their home? In New Home? That hardly made sense to Sans. What little he remembered of their Snowdin house and why he chose it to begin with was because of their feeble income. He could afford their quaint little shack buried in the snow; he could never dream of purchasing anything in New Home – or so he thought.

"Are you okay?" Papyrus pushed, peering closer, "You haven't been working yourself too hard, have you?"

"no…i don't think so…" Sans mumbled, glancing at the ground in concentration. He really couldn't remember anything about what he had been doing with Papyrus at the time he had been teleported back to the past. He didn't know why they were in New Home at three in the afternoon nor why his brother opted to parade himself in basic garb. For some reason, he thought he would be able to remember what he was doing when he would be brought back, but that was foolish of him. After all, the Dog had said he would bear all of his _current_ memories; he made no mention of his past ones.

"You're acting strange…" Papyrus noted. "Are you sure you're alright?"

"yeah, i'm…" Sans trailed off when he suddenly remembered why he was where he was. The Dog and Frisk had arranged to send him back in time to save – "i've got to go see Gaster!"

The declaration was both abrupt and unexpected. Papyrus stumbled back a few steps, looking all the more confused. However, Sans didn't want to deal with the thousands of questions that he would likely be voicing. He had to see Gaster. The simple thought of finally being able to do so after so long had his soul heart thumping madly in his chest. He glanced back from where he presumed they had come from. He didn't recognise the road, but he was sure he would be able to find his way.

"What—why?" Papyrus demanded predictably, "You were _just_ with him—"

But Sans didn't even grace him with an explanation. He darted down the road desperately. He ran as fast as his legs could carry him, nearly tripping multiple times in his rush to return to the lab. He didn't really think about where he was going; his body seemed to know the way like it had been ingrained in it. Sans took a sharp right turn, squeezed through a narrow alley, ran down a populated road littered with little independent shops, and then took another right. He was hardly aware of Papyrus shouting and running after him. At the time, all he could think about was seeing Gaster again.

Somehow, he found himself in front of the main elevator. A small group of people were huddled in front of the doors, waiting for them to open. If Sans waited after them, there would surely be no space for him to descend. Thus, he pushed his way through and when the doors opened, he practically fell in. The monsters grumbled angrily, shaming him for his impoliteness, but he didn't care. He just wanted to see Gaster. It was the only thing on his mind. Sans pressed the button to shut the doors as quickly as possible, leaving no time for any other monster to gather their things and enter. However, Papyrus had still managed to squeeze himself through at the last second. He was positively out of breath and glared at Sans.

"What's wrong with you!?" He scowled angrily.

"i-i have to see him…" Sans stammered anxiously. His hands – his entire body was shaking.

"Why?" Papyrus demanded as the elevator jerked into motion. They began their long descent. "You were _just_ there. Why do you need to see him when you could have just called him?"

"you wouldn't understand…" Sans mumbled and tapped his foot impatiently. The elevator was moving too slowly. It needed to go faster.

"Sans—" Papyrus growled in annoyance and stepped in between him and the elevator doors. He stood akimbo, ready to keep the smaller skeleton from leaving until he was satisfied with the answers he was given. Sans had no patience at the moment, not even for his brother. "What's wrong?"

"nothing—" he tried.

"I don't believe you!" Papyrus countered immediately. This Papyrus was far more stubborn than the one he was used to. "Look at you! You're completely panicked! Does it have anything to do with the machine? Is something wrong with it?"

"machine…?" Sans repeated curiously. Was Papyrus talking about the one that lead Gaster to his doom? How much did he know about the experiments they had been up to?

"The one meant to bring down the barrier." Papyrus specified, "Is there something wrong with it?"

Sans could hardly believe he had ever shared such information with his brother. As much as he loved him, he made a strict point to tell him nothing. It was for his own good. Papyrus wouldn't be able to handle the truth – let alone _remember_ it. And yet, somehow he knew. He knew about their plans to bring down the barrier through mostly science, partially magic. Why did he know?

Suddenly, the elevator halted its descent and the doors slid open. Papyrus was momentarily distracted by this which gave Sans the opening he needed to push by. He easily slipped past his brother, much to his anger and protest, but he didn't stop. He couldn't stop. He absolutely had to see Gaster. It was the first time he felt a desire so strong he thought it might kill him if it wasn't fulfilled. It was the only thing plaguing his mind and stifling any other rational thought he could have been having. He had to see Gaster. He simply had to.

The smaller skeleton ran through the Core, nearly smacking into monsters whenever he turned corners. Papyrus shouted after him to slow down, but he didn't listen. He _couldn't_ listen. Before long, he was out of the giant structure and running through Hotland. The soft soil slowed his pace only slightly, but it wasn't too much of an issue given how he only needed to reach one last elevator. If he was lucky, he would be able to shut the doors before Papyrus entered. He dashed into the machine, smacking the buttons to bring him to the lowest level and close the doors. It almost seemed like his brother wouldn't make it in time, but he managed to shove his hand into the thin gap, effectively prying the doors open just enough to squeeze in.

"Sans!" He growled again, gripping him by the shoulders this time, "What's your problem!?"

Sans didn't need to answer. The moment the doors shut, the elevator was in motion and it was as unstable and shaky as he remembered it to be. The machine quaked so much, it threw Papyrus off balance. He fell on his butt, narrowly avoiding bumping his head against the wall. By the time he recovered, the doors were open and Sans was running again and now there really was no stopping. He could see the lab stick out in its red-brownish surroundings. He never did understand how the bright silver remained so pristine despite the dust and heat. Not that it mattered.

He ran through the doors, slamming into someone with so much force he found himself knocked back on the ground while papers rained onto him. Sans groaned, pushing himself up slowly and rubbing his head, which had suffered a great deal of the impact. He was about to mumble an apology when he was silenced by the sight of the person he had hit. Alphys stared back at him with a confused expression while she rubbed her sore forehead.

"A…Alphys?" He asked, unable to hold his tongue. Even when he couldn't remember something, a feeling of having once known about whatever was forgotten remained. As such, even though he had no memory in certain resets, he knew at some other points he had. However, Sans had never experienced such a feeling with Alphys. "you're…you work here…?"

"Yes…?" She returned quizzically, just as the lab doors opened to allow Papyrus entry.

"Sans!" He scowled.

"What's going on?" Alphys asked, slowly finding her way to her feet.

"Sans has gone mad; that's what's going on!" Papyrus stated, throwing his hands up in exasperation.

"hold on, you _work_ here?" Sans insisted. He couldn't quite wrap his head around the notion. Why didn't that little fact remotely _feel_ like it had once been something he knew?

"Yes, why do you keep asking me that?" Alphys answered again.

"See what I mean?" Papyrus said.

"for how long?" Sans questioned, "did we know each other? are we friends?"

"What's with this line of questioning?" Alphys asked, now very concerned, "You should already know the answers. What's wrong? Are you okay?"

Despite not knowing, Sans understood Alphys was more focused on getting some answers for herself rather than providing any. Not to mention, she was currently slowing him down. "i have to see Gaster." He simply replied. He could feel Papyrus rolling his eyes behind him. "where is he?"

"Probably in his office—"

And she had hardly finished her answer before Sans found himself running again. He heard her cry out, demanding to know what was wrong only for his brother to answer that he wanted to know the same thing. Alphys went off on a tangent, anxiously wondering out loud if something had happened to Gaster to merit this sort of reaction. The truth was yes, but it hadn't happened _yet_. Hopefully, it wouldn't happen at all.

The corridors through which Sans ran were both familiar and unknown. The scarce people he came across were more of the latter. They gave him strange looks, moving out of his way in the nick of time while murmuring to themselves the questions Alphys was likely shouting behind him. It didn't slow him down in the slightest. His soul heart was beating wildly, so much so it felt like it was steadily breaking through his rib cage. Finally, he found the door on which Gaster's name was engraved. Sans didn't pause for a second; he practically broke it from its hinges as he barged in noisily.

"Wha—I-I wasn't sleeping! I swear!" Gaster cried out, startled out of his snooze by Sans. The small skeleton stood in front of him petrified. "S…Sans?"

He had imagined time and time again what he would say or do if he ever got the chance to see Gaster again. It was only now that he realised whatever scenarios that had crossed his mind were the product of a false image of himself. Sans couldn't crack the puns and lame jokes he always thought he would. He couldn't even take a step forward or backwards. He was stunned in place, his eyes fixated on the man – the monster that had been away for a handful of years, but also centuries. It had been so long and though Sans knew and understood what he was seeing and living was real; he struggled to believe it. He had dreamed of this moment so much and sometimes it had felt so genuine; how was he supposed to distinguish reality from fantasy when both were so similar?

"you're…here…" Sans whispered and he wasn't quite sure why. His voice was choked and limited by the intense mix of emotions paralysing him.

"I…I am…" Gaster agreed uncertainly. He seemed confused. "Was I…not supposed to be?"

The truth Sans hadn't yet been willing to admit to himself was that he couldn't remember what Gaster looked like when Frisk was first questioning him about his memories. The monster that stood before him was twice his size – maybe a little taller – with thin but elegant features. His skin was as white as the Snowdin snow, and his eyes were like the night sky – sparkling white irises against a black backdrop. He wore a while lab coat under which was a black turtle neck and beige dress pants. Sans made sure to engrave every single detail into his memory, refusing to forget him ever again.

"Why is he acting like that?" Alphys whispered to, presumably, Papyrus.

"I don't know…" The latter replied, equally confused, "He last saw him thirty minutes ago but he's acting like it's been forever."

But Sans didn't pay attention to them. He couldn't. He was so focused on Gaster that their voices had shrunken into nothing. They were barely perceivable muffles smothered by the thick, noisy beating of his soul. The only thing he could hear clearly was Gaster and, currently, he wasn't much for words.

The monster in question rose from behind his desk slowly. He pushed his desk chair back as he made his way around the table, a look of concern present on his face. Sans sucked in a sharp breath. It had just hit him that his behaviour was indeed odd. It was as Papyrus had said, to them it had been somewhere around thirty minutes since they last spoke and saw each other – but it wasn't the case for Sans. He was the only one in the room that had gone centuries, maybe longer, without having a real conversation with or even being able to touch Gaster. And now that he was so close, the small skeleton couldn't stop his hand from moving to graze his face. It was as though sparks went off when his fingers touched his cheeks. He could feel the emotion bubbling over and tears threatening to spill from his eyes. It had been so long and Sans now knew he wasn't dreaming. Gaster was right there.

"Sans…? Are you okay?" Gaster asked tensely.

"yes." He smiled and, for once, he really felt it. He was going to save Gaster.

"Then why did you run here like a madman?" Alphys asked bluntly.

"I would also like to know." Papyrus seconded.

"i had to see him." Sans answered, eyes still glued to the taller monster's face.

Gaster blushed a bit, blinking rapidly in surprise.

"I feel like this is weirdly taking a romantic turn…" Alphys commented, eyes shifting away.

"it's not." Sans assured.

"I'm just saying I support this evolution in your friendship." Alphys stated, raising her hands submissively.

"W-well," Gaster started, clearing his throat awkwardly, "I'm glad I mean so much to you. It makes me happy even though you almost gave me a heart attack."

"Did we really run all the way here for you to be platonic with Gaster?" Papyrus asked, grimacing.

"no." Sans replied, shifting his stance as he got serious. There were so many ways he could go about trying to save Gaster. The most logical one seemed to be to tell the truth. If Gaster weren't a scientist, Sans might have opted for a different approach. However, the monster in question was exceptionally smart and could be convinced. With any luck, one long conversation would be all it took to end this stupid game. "Gaster." He said, "we need to talk."

OoO

"what do you mean you don't believe me?" Sans demanded. He wasn't quite as frustrated as he was upset and confused.

Gaster had taken his seat back behind his desk. His legs were crossed and his arms were folded tightly over his chest. He bore an uneasy expression which could also be found on Papyrus's and Alphys's features. The last two shifted awkwardly next to the Royal Scientist in question as though searching for words that wouldn't upset Sans.

"You're claiming you're from the future," Gaster said slowly. He uncrossed his legs and leaned forward to press his elbows on his desk as he gesticulated. "Now, as a scientist, I'm open to the prospect and the possibility. After all, the machine we're just about finished building _is_ a time machine. However, you haven't supplied us with any proof to back up your claim."

"Yeah, you kind of just sound crazy…" Alphys unhelpfully added.

"It's worrying." Papyrus nodded.

Sans's shoulders dropped. They had just had a long conversation during which he explained everything – with the exception of Frisk and the Dog sending him back – and no one had made even the slightest interruption. Gaster, Alphys, and Papyrus had listened to him respectfully and at times it really seemed like they believed him. Sans could feel panic begin to swell in his chest as his mind wandered to the possibility of having to live through another reset. His goal was to save Gaster on the first try to avoid torture. Now that his first plan, which had seemed so fool proof, was failing, he didn't know what he was going to do. He couldn't remember anything about his life at this time and so he couldn't give them the proof they needed to believe him.

"i-i haven't been here in a very long time—" Sans tried vainly – desperately. "isn't the fact that i can't remember things i should know proof enough in itself…?"

Gaster leaned back into his desk chair. "I think I know what's going on here…" he claimed, "You're nervous about D-Day. As you should; rewriting the laws of physics as we know it shouldn't be taken lightly."

"Then again," Alphys muttered mostly to herself, "did the laws of physics ever really matter down here?"

"Good point." Gaster acknowledged, nodding in her direction, "The fact of the matter is this: in three days, we're literally going to rewrite history and we can't be certain of all the repercussions that simple but big action will bring. That's a lot of pressure on our shoulders, especially when all we really want is to bring down the barrier – or rather, stop it from ever being built. That pressure and anxiety," he pointed towards Sans's forehead, "can cause stress-induced memory loss."

"It's not going to be permanent, is it?" Papyrus asked, concerned.

"It's definitely temporary." Gaster assured, "And, as a doctor, I am prescribing a night's worth of rest to get you back on track. Maybe a full day, if you want."

Sans wanted to argue. He wanted to stand his ground and force Gaster to believe him. He wanted to shake sense into him; to scream he was going to die if they didn't pull the plug now. However, he knew it would amount to nothing. There wasn't even a point in telling them about Frisk and the Dog now that they firmly believed he had cracked beneath the pressure of their work. As much as he didn't want to, Sans would have to admit defeat for his first tactic. The best he really could do for the moment was to go home with Papyrus and think of another approach.

 _It's not all lost yet…_ He told himself to maintain his morale, _I've still got three days…_

"yeah." Sans said, "you're probably right. i'll go home."

Gaster smiled softly at him. Despite his apparent failure, that simple gesture comforted Sans. It had been so long since they last spoke. Even if this conversation hadn't unfolded the way he had intended it to, by God did it please him to have finally talked to the Royal Scientist. He cherished the moment and allowed it to fuel him. Sans was going to succeeded. He was going to save Gaster. He _had_ to. And once he did, they could have plenty more conversations.

"Are you sure you didn't also come here to declare your love, or something?" Alphys probed. "You've literally been staring at him for a solid two minutes."

"see you tomorrow." Sans sighed, electing to ignore what the yellow monster had said.

Sans and Papyrus walked out of Gaster's office together. It was a bit difficult to hide his disappointment in that moment. He had set his hopes too high. He had wanted to succeed too much on the first try, ignoring how statistically impossible that was. He needed to be more realistic with himself but, more importantly, he needed to think his plans through thoroughly before attempting them. It would lessen the amount of times he would have to think of a new tactic. As it was, telling the truth would now only be useful if Sans suffered a second reset at which point he might be able to supply enough evidence to convince them he was from the future. Hopefully, it wouldn't come to that.

 _I've still got three days…_ Sans reminded himself.

The walk to their home was generally quiet. Sans walked a step behind Papyrus mostly because he didn't know where they were going. He might have been able to rely on his instincts to guide him to the lab, but it wasn't as though he wouldn't have been able to manage without it. New Home was still New Home and Sans knew how to navigate it decently well. He had a handful of location markers to help find himself in case he got lost on one of his routine visits to the castle. That being said, the small skeleton had no clue where it was they lived in the crowded city.

Sans reckoned it couldn't be lavish home. They were probably located in the poorer neighbourhood with cheaper prices for apartment flats or town houses. It was also probably small; if not because it was less costly, then because New Home was running out of space to expand. Sans wondered if he had still managed to afford a room similar to the one Papyrus had in Snowdin with whatever little money he had. He glanced at the tall skeleton quickly, assessing the quality of his clothes. They looked well kept. There were no patched up holes or faded stains. Papyrus's boots even looked new. He supposed it was fair to assume that yes, he probably had.

Thus he shoved his hands into the pockets of his lab coat and sighed, turning his gaze to his surroundings. Sans decided it was probably for the best that he try to memorise the route from his home to the lab. It wouldn't do to waste time aimlessly wandering around because he hadn't bothered to be attentive. He only had three days, after all.

The brothers walked through Hotland, taking an elevator directly to the Core before hopping onto the last one to New Home. They had to wait a couple of minutes before the machine made its way down to them, releasing only a small handful of monsters that were likely making their way home after a long day of work. Sans and Papyrus were the only two monsters to enter for the long ride up. No words we exchanged during the final ascension but Sans did sense a bit of tension from his brother. He peeked at him only to find a frustrated expression paved on his face. Sans said nothing about it. If Papyrus had a problem or was upset about something, he would tell him of his own volition.

When they left the elevator upon arriving to destination, they began walking down the path Sans had initially run through in his desperation to see Gaster again. He glanced around, captivated by the beauty of the architecture of the buildings and recreational areas they walked by. He had never gotten to see much of it on his infrequent trips to the castle as it wasn't on his way. The skeleton was so enticed by his surroundings – and all the more bewildered he could truly afford a home in such a city – that he was separated from Papyrus. He hadn't noticed they had entered a busy street and Sans panicked a bit as he searched around for his brother. He couldn't see him through the hustling and bustling of the sea of monsters surrounding him.

"Sans." Papyrus said sternly, startling the skeleton in question as he gripped his shoulder. Sans turned to face him, intimidated by the expression he bore. It was almost like his brother was upset with him.

"sorry, bro." Sans apologised, trying to sound as nonchalant as possible, "i got a bit distracted…"

Papyrus frowned at him. Despite being different from what he was used to, Sans could still read him like a book. The tall skeleton doubted the excuse he had supplied but thankfully said nothing about it. Instead he turned on his heels and began making his way down the opposite direction Sans had been about to wander to. "Come on." He simply said.

They travelled down the busy road for a few long minutes. Sans struggled to keep up with his brother's long strides, silently cursing his shorter legs. Then they took a left and happened upon the market place Sans had run through earlier. It would have seem the sharp turns in narrow alleys had been mostly unnecessary albeit faster. Then again, how had he been supposed to know that when he had hardly any memories of this period in his life?

Where there were already a lot of monsters before, there were plenty more now. Sans could hardly take a step without bumping into someone. Disaster almost struck when an anthropomorphic cat monster had nearly dropped her grocery bags, but Sans had been quick enough to catch her belongings before they fell. He consequently kept close to Papyrus, glancing around and catching glimpses of the shops and portable shacks lined on either side of the road. Most merchants seemed to be selling food but Sans noticed a couple of artists advertising their work and also taking in the moment commissions, and artisans selling handmade bags or fashionable clothes. It was mesmerising to see so many people go about their day to day lives in such an environment.

After another left turn and passing by the clock upon which Sans had first found himself, it was a short walk to their apparent home. The skeleton brothers followed the winding road of cobble stone down to a far less crowded area. The lights hanging on the cavern ceiling began to dim marking the slow fade into the night just as Papyrus stopped in front of a surprisingly luxurious establishment. Sans regarded it with awe. It looked like one of those nice Italian buildings he saw in some of the human magazines Toriel had laying around her surface home.

"whoa…" Sans muttered to himself. There was no way they lived in _that_. It was just impossible; there was no way he could actually afford it.

"Well?" Papyrus impatiently asked, glancing down at him. Sans stared at him dumbly, which then caused the former to sigh. "Did you lose your keys again?"

"wha—uh…" Sans stammered, quickly patting himself. "no, i don't—ah!" he fished out a pair of keys from his lab coat, assuming they served to unlock the front door.

Papyrus rolled his eyes and was the first to wander up the front steps, moving to the side to allow Sans access to the door. The latter followed suit, inspecting the keys he was holding to see which of them was probably the right one. However, the longer he took to come to an answer, the more irritated his brother seemed with him. He didn't know why Papyrus was reacting so negatively to him at the moment and so, in an effort to avoid any more rising tension, Sans just started trying all of them. Fortunately, the second time was the charm. The key slid in the hole and the lock clicked open when Sans twisted it towards the left.

The small skeleton held the door open for his brother, quickly following him in and up the stairs. They climbed three levels of the apartment building before Papyrus made for the door giving out on all the flats. They walked through the corridor and stopped in front of door 314 at which point, the tall skeleton returned his gaze to Sans expectantly. He now understood what his brother wanted of him and hardly hesitated to try in the key he had used earlier only to find it didn't fit. He glared at it in frustration, nervously picking a different one in the hopes it would unlock the door. Unfortunately, Sans had to try all of them before happening upon the right one. Papyrus was positively annoyed by the time he could finally enter their apartment home.

Speaking of, the sight of their flat made Sans absolutely speechless. The skeleton had expected a small run down place with creaky floor boards, banged up walls, and little to no furniture. Instead, he found himself beholding a properly furnished and rather spacious area. It was nothing fancy, tailored to near exact precision to Sans's tastes. It actually mimicked how he would have liked to have their Snowdin home if he could have afforded it. The walls were covered in a nice layer of dark blue, Bordeaux, and light yellow paint. They had a nice couch, a carpet, and a TV in the living room. From the aforementioned area, one could see the kitchen, which was surprisingly big. There was also a large counter separating it and the living room and, judging from the stools, it seemed to serve as their dining place.

Sans slowly moved around, inspecting everything that was apparently his in complete wonder. He couldn't believe he could actually afford all of this. They even had a balcony to the left of the couch on which was a patio table with a bouquet of echo flowers. Now he could hardly imagine what his room looked like. Surely he had sacrificed comfort for a very cozy and pretty home. The skeleton thus wandered to where he saw his brother leave from the corner of his eye. To the right of the kitchen was a small corridor with two doors facing each other. He opened the one on his left, astonished to find his room was the exact opposite of the one in Snowdin. He actually had a bed frame and bed sheets – though the latter were still sprawled about messily. He had a proper desk and dresser. What's more, Sans also had a wall dedicated to all of his accomplishments and pictures of his friends. Naturally, he wandered to it first.

His eyes initially wandered to the diploma around which pictures of various moments of his life had been placed. He had graduated with high prestige from the New Home University, consequently obtaining a PhD in astrophysics. Just below it was a picture of he, Gaster, and Alphys wearing their graduation garb and holding their diplomas. Judging by the lack of her presence in a grand majority of the pictures, Sans concluded he had met the yellow monster in University. The rest of the images were mainly of Gaster and Papyrus ranging from when they were in kindergarten to recently. The skeleton glossed over the images in mesmerisation, brushing the tip of his fingers over them. He didn't quite understand why he had dedicated an entire wall to photographic memories, but he had a feeling it was his source of motivation.

Sans smiled fondly at the wall. He was filled with warmth, though it was a pity none of the images could spark even the barest hint of memories. It was then Sans realised how truly little he remembered of this period in his life. All he had known was that he had been Gaster's assistant and best friend. The skeleton had noted so many discrepancies with how he knew things to be and how they were presented to him in this time. He hadn't remembered Alphys ever being remotely present in his social circle nor Papyrus being so unlike himself. It was strange to behold and Sans doubted he would ever truly wrap his mind around the differences by the time he saved Gaster.

The skeleton's thoughts were momentarily interrupted when he heard the door to Papyrus's room creak open and shut as he left it. He listened to his footsteps trailing to the kitchen before wincing at the screech of one of their stools being pulled back. Sans gave a last glance at the pictures on his wall as his hand wandered to his stomach area when it growled. Despite how everything was so different, at least he could look forward to the familiarity of Papyrus's terrible cooking.

Sans turned away from the wall, knowing very well he would likely spend the night looking over the photographs, and joined Papyrus in the kitchen. He found his brother as expected: on the leftmost stool with his elbows on the counter. The tall skeleton was lost in his thoughts, face scrunched in a sort of uneasy grimace. Sans wondered what was bothering him, but he knew better than to pry.

"you hungry, Pap?" Sans asked instead, cocking his head inquisitively as he strayed closer.

Papyrus jolted out of his thoughts, snapping his gaze in his direction. "Yes." He responded simply.

There was a brief pause wherein the two exchanged expectant looks. Sans didn't understand why Papyrus wasn't getting up to make spaghetti whereas the latter was confusingly glancing between he and the kitchen.

"do…do you want to have some spaghetti?" Sans asked slowly, hoping it would coax his brother into action.

"Yes." Papyrus replied again and after a moment he added: "The pasta is in the cupboard."

"oh…okay…" Sans nodded slowly, shifting in place. A weird silence fell over them; Papyrus seemed as confused as Sans felt. "i…i guess i'll just…get to it…?"

"Okay." Papyrus said.

Sans gave his brother a weird look before slowly trudging into the kitchen. Was Papyrus really expecting him to cook? The tall skeleton typically jumped at the opportunity to make spaghetti, always shooing Sans out of the kitchen to have his space. Were things different in this time period? Was Sans more responsible than he thought and did he really cook for them? If that were the case, he hoped he wasn't too excellent of a chef because he was really about to let Papyrus down.

Sans looked at the cupboards slightly daunted by the amount. Some were far too high for him to reach. He really hoped the dry noodles weren't in those ones, but he supposed Papyrus would have fetched them for him if it were so. His brother wasn't mean enough to watch him struggle for something beyond his reach. Sans instead looked to the cupboards directly next to the refrigerator. It seemed logical to keep all the edible food in the same area and so he decided to open that one first. He luckily found the dry noodles he was looking for. However, that was only the beginning of his trial. He needed to find a pot and make the pasta sauce.

And as fate would have it, the skeleton spent a ridiculous amount of time fishing through every cupboard to find what he needed. He refused to look back at Papyrus, already anticipating the strange look he was probably giving him. He had already spent way too long looking for a pot and now he was trying to start the sauce. The main problem Sans was dealing with was trying to figure out how to make it. He had taken out a couple of vegetables but wasn't if they were all necessary. Beets didn't seem right, but he had already taken them out from the refrigerator and felt like he had consequently committed to them.

 _This is going to be really gross…_ Sans thought to himself, cringing.

"Did you…did you really forget how to make pasta sauce?" Papyrus asked incredulously.

"erm…" Sans hesitated. He might as well come clean. "this is very stressful for me…"

Papyrus sighed loudly, hopping off his stool. Sans watched as he started fishing out the proper ingredients from the refrigerator while casting the wrong ones away. His brother's movements seemed impatient and harsh. Sans felt bad for having angered the other, but couldn't apologise if he wasn't told what he was doing wrong. He took a step back and watched Papyrus carefully. Perhaps he ought to put his patience aside and confront his brother directly. Things weren't going to get better by waiting around.

"hey, Pap…" Sans started slowly. He was a bit nervous about taking the initiative when Papyrus already seemed so irritated. However, the latter ignored him as he began chopping a tomato into big chunks. That was strange. "Pap…" he repeated.

Papyrus abruptly slammed the knife down against the counter, startling Sans. He watched him anxiously petrified in place when he noticed how his shoulders starting to shake gently. Soon after, the small skeleton could make out gentle sobs. A pang of worry stabbed at his soul heart instantly as his brotherly instincts began to kick in.

"Pap…" Sans said soothingly as he approached him.

"I-I'm sorry…" Papyrus sobbed. He tried to wipe the tears away from his face as though to hide he had ever cried, but it wasn't working.

"it's okay," Sans reassured, placing a comforting hand on his arm, "what's wrong? did i do something?"

Papyrus shook his head, sobbing for a bit longer before he regained his composure enough to confess what had been upsetting him. "I…I haven't been doing so great at…" he swallowed thickly, "the Royal Guard Training Academy."

Sans held in his surprise. _That's a thing?_ "yeah?" He ushered.

"I'm trying my best…" Papyrus explained, "I try to be better at fighting, but I'm not…and…and the other recruits pick on me because of it…" he took a big shaky breath, "they tell me I'll never be a Royal Guard…that I'm a loser, I'm unpopular, and no one will ever want to be my friend…"

Sans was frankly shocked by the confession. How could anyone be so mean to his little brother? Papyrus was the best – he was kind, supportive, and loyal above all. To hear people had the audacity to bully him relentlessly like that filled him with absolute anger. He ought to give them a bad time…but that wasn't the mature solution, or the solution that wouldn't result with Papyrus's expulsion from the Academy.

"we've got to tell a teacher." Sans declared sternly. "they can't go unpunished—"

"Don't you think I've tried, Sans?" Papyrus asked, "The teachers don't care…I think some of them think I deserve it…maybe I do…"

"don't say that." Sans said. It broke his heart to see his brother so upset. "no one deserves to be treated badly. especially not you."

"Then…why do they do it?" Papyrus asked.

"some monsters are just garbage." Sans stated, "those ones, the ones that hurt you and the ones that ignored you when you asked for help, they're the worst kind of garbage. the last thing they should ever come to be are members of the Royal Guard when they're abusing their power rather than helping others like they're supposed to."

"What…what am I supposed to do?" Papyrus asked helplessly.

"you keep being the best guy i know." Sans encouraged, "keep training and putting your all into it. i'll find a way to get those bullies off your back, i promise."

"What are you going to do about it?" Papyrus asked, doubtful.

"i'll figure something out." Sans assured, "i've got connections. but, for now…" he took the cutting board and the knife, "let's try making this pasta sauce together."

"Okay." Papyrus agreed, giving a small smile.

* * *

You watched as Sans tried to crack some jokes to lighten up the mood. He only angered Papyrus, but you recognised his annoyance as the one he forced rather than the one he actually meant. He was doing better and that was good. Hopefully, Sans would find a way to solve his brother's problems. That being said, you still kind of wished the Dog could have teleported you back as well to offer a helping hand. It really wasn't right that people were bullying Papyrus when he was so great.

"Oh ho!" The Dog chuckled to Himself. "I have to admit, I didn't remember this at all! Interesting!"

You gave the Dog a puzzled look. You didn't understand why He was so amused.

"Don't you see, Frisk?" He insisted, "Sans is getting _distracted_. He feels committed to helping his dear brother. That's time consuming, you know. Now he'll have less than 72 hours to dedicate to W.D. Gaster."

"He can't just abandon Papyrus." You replied firmly, "It's wrong to not help someone when you know you can."

"Of course it is, I'm not saying the opposite." The Dog assured, "But the more Sans feels obligated to help others, the more he'll lose focus on why he was sent back to begin with."

"Papyrus is his brother." You asserted.

"But he turned out all right in the end, didn't he?" The Dog pointed out, "Between the two of them, Gaster's the one who really got the short end of the stick."

You felt angry to see the Dog trying to justify why Sans should leave Papyrus to a bad situation. And yet, you also understood where He was coming from. The look in His eyes reminded you of the bet you had going on. Unlike Him, you had something to lose if Sans got lost in his obligations to Papyrus. So did Sans, you also reckoned. The more resets he suffered, the more likely he was to call it quits. But you shook those thoughts out of your head decisively.

"That's still no reason to abandon Papyrus." You maintained.

"Perhaps." The Dog conceded, "But he might have to if it means saving Gaster."

He turned His attention back to the skeleton brothers. They were heating the sauce and draining the water from the pasta. Soon they would be eating their meal and heading off to bed. Papyrus was in a considerably better mood now. Sans also seemed a little relieved.

"I wonder…" The Dog mused aloud, "Who would Sans choose to save between Gaster and Papyrus?"


	3. Blind to the Truth

When Sans opened his eyes, he found himself lying on the floor of what was apparently his room. It looked nothing like the one in Snowdin with its messy floor, self-sustaining tornado, and litter of socks, but he knew it to be his somehow. It took a long confusing minute for him to remember where and _when_ he was. The Dog and Frisk had sent him back in time to save Gaster. 16 hours had now passed and thus commenced the first full day Sans had to convince the Royal Scientist to stop his experiment before it was too late.

The skeleton pushed himself into a sitting position, stretching his limbs. He was just about to get up when a photograph fell from his stomach to the space in between his open legs. Sans tilted his head curiously and picked it up. He looked at the photograph of he, Alphys, and Gaster in the strangest, most colourful clothes and shades he had ever seen. Given the dark background with neon lights, Sans had concluded before falling asleep that this had likely been snapped at a university party. He then glanced from the picture to the wall in front of him, easily finding the empty spot where it had once hung.

Sans pushed himself from the ground and hooked the picture back in place. He must have fallen asleep in the midst of investigating the photographies. He had barely gotten through half of them the previous night, but they all seemed to depict fond memories. Sans wished he could remember them. He looked at a picture of he, Gaster, and Papyrus before moving to his dresser.

Today was a new day and Sans had to, once again, attempt to save Gaster. His first plan hadn't gone over so well. Actually, it had back fired. Instead of believing him, the Royal Scientist in question now firmly believed Sans had suffered some sort of mental breakdown. As disappointing as it was, he couldn't let it beat him. It wasn't over yet and no matter how many more times he would or could fail, he had to keep that in mind. Sans would inevitably succeed. He just hoped it wouldn't take more than a reset.

As such, Sans pulled on some fresh clothes from his dresser before covering the ensemble with his lab coat. Once ready, he left his room and made his way for the kitchen where he found Papyrus. The latter was already seated at the counter eating a bowl of protein cereal. He sparred him a quick glance and smile upon noticing his arrival, though he soon turned back to his breakfast. Sans pondered on whether he should also eat something, but, despite his determination, his nonexistent stomach was in knots. He was still too anxious about his situation to eat anything.

"No breakfast?" Papyrus asked between big spoonfuls as Sans took a seat next to him. "That's not healthy, you know."

"eh, i guess i just don't have the _stomach_ for it." Sans smirked and winked.

Papyrus groaned and rolled his eyes. "At least you're in a good mood…" he muttered.

Sans snickered and watched his brother. He was nearly done his bowl of cereal and soon they would both be leaving for their respective occupations. It was then that Sans remembered the Training Academy and the bullies. He could hardly believe he had actually forgotten. His eyes drifted back to the taller skeleton, now noticing small quirks that had eluded him. There was a small tremble to Papyrus's grip and his body was very tense. He probably didn't want to go to the Academy today. Or ever again, if he was treated as badly as Sans thought.

"Pap…" Sans started slowly.

"I'm almost done, just give me five minutes." Papyrus assured, shovelling the food in his mouth.

Sans winced a bit. He felt horrible for his brother. "hey…" he continued, pressing his hand to his back in an action meant to be comforting. "it's going to be okay. you're going to have a good day."

Papyrus stiffened and halted his movements. Then, he swallowed thickly and pushed his bowl away. "I probably won't." he smiled bitterly, and it broke Sans's heart.

"i'll fix it. i promise." Sans swore.

"I believe you." Papyrus said.

He brought his empty bowl to the sink and cleaned it quickly. Once it was back in its respective cupboard, the brothers left their apartment. Again, Sans found himself following Papyrus. Though he was more familiar with the path, he suspected they were going to walk together the whole way. If Sans was still remotely like his current self, he would have wordlessly agreed to walk a detour all the way to the Training Academy for his brother. And, as he soon learned, that was exactly the case. They passed by the small clock tower and crossed through the market place before weaving their way through a confusing set of streets. They zigzagged around tall buildings for ten whole minutes before happening upon an open space in the center of which was the Royal Guard Training Academy.

The school closely resembled the ones Sans typically found in Alphys's mangas. It was a large, rectangular structure with many large windows, surrounded by a gate. Beyond the gate was a cement path leading directly to the front doors, however the middle of it was obstructed by an obnoxious fountain. The large sculpture of a knight with their sword erected towards the sky was the center piece and Sans could only roll his eyes at it.

"Well…this is it." Papyrus remarked tensely. He straightened his posture and fixated his gaze on the Academy, determined to face his impending torture head on. "Have a good day, Sans."

Sans regretfully watched him go. No sooner had his brother crossed the front gates did a group of monsters seemingly pop out of nowhere, calling out the tall skeleton's name and waving at him. It would have been nice had it not been for their sneering and taunting tones. Sans clenched his hands into fists as he forced himself to turn away. Physical pain explode in his chest; he felt like he was turning a blind eye to his little brother the same way everyone else in that stupid school had. Even if Sans absolutely planned to fix the bullying situation, he still felt like garbage.

 _I can't do this to myself right now…_ Sans sighed deeply and glanced around. _I've got to save Gaster first._

The skeleton quickly spotted the tip of the elevator shaft he was meant to take to the Core in the distance. It was the only familiar thing he managed to recognise, which was good because he would have otherwise spent a lot of time trying to find his way. He consequently walked to the elevator, moving about in unfamiliar roads with his eyes trained on his destination. Once he got there, he was presented with a small crowd of monsters embarking on the machine. Luckily, there was enough space for him to squeeze in and soon they began their long descent.

He wasn't sure how he was going to go about convincing Gaster to call off the experiment this time. He had thought his first plan would have worked perfectly, but he apparently lacked the adequate proof to back it up. It was frustrating but now he knew what they expected of him. Whatever Sans did next, he had to be certain that it was irrefutable. But how? What was he going to do now? Gaster was a man of logic and reason. He could be convinced with the right proof, but Sans wasn't sure what it was he ought to prove.

 _proof…_ Sans pondered to himself. And then, an idea struck him.

As soon as the elevator doors open, he bolted out and dashed to the next one he would need to take to reach the lab. After a shaky and unstable ride, he found himself running into the lab where every scientist Gaster had in his team were seemingly running about like chickens without heads. They brandished papers, boxes, and electronic devices around while screaming science jargon to one another. It was the last thing Sans had expected to see. He didn't remember there being so many monsters working together under his best friend's management. Then again, there was a lot Sans didn't seem to be capable of remembering.

"Sans!" Alphys shouted and ran towards him. She held a stack of boxes about twice her size. "How are you feeling?"

"much better now." He admitted. "where's gaster?"

"Last I saw he was in the True Lab with his head mechanic." Alphys mused, "They were discussing the Core's heat levels and he wanted to inspect it, maybe change a couple of used pieces, and tighten some bolts, that sort of thing."

"is he still here?" Sans asked, glancing back at the door.

"I think so—" Alphys started when her eyes caught something just over Sans's head. She smiled, "Speak of the Devil."

"Alphys! Sans!" Gaster excitedly exclaimed as he dashed to them, his mechanic in tow. He looked at Sans, "Are you feeling better?"

"Yes—" Sans answered.

"Great!" Gaster grinned before Sans could get another word in. "You know, your breakdown got me thinking…we should all come up with, like, key words or something we can only use if we become time travellers. That way we'll know one of us is from the future and has come back."

Sans deadpanned. "what."

"I was thinking the same thing!" Alphys shouted animatedly.

"Sir, is this really the time?" The mechanic, a blue bird monster, asked with an unimpressed look on his face.

"Yes, Naiman!" Gaster insisted, "There's no better time! Don't be a buzz kill and think of your key word."

Naiman rolled his eyes and opted to simply stand there while Gaster wrapped up his tangent. Strangely, Sans remembered the Royal Scientist as a more stoic and calm individual, not as some hyper nerd speaking a hundred miles an hour to seemingly keep up with his thoughts. Sans reckoned it was a very Papyrus-like quality, which was refreshing.

"I thought of mine last night!" Alphys giddily informed. She dropped her boxes on the ground, likely in the anticipation of a long conversation. Naiman sighed and rolled his eyes again at the gesture. "So if either of you come back from the future, all you've got to do is tell me 'sexy fish' without context."

Sans snorted at that. "why don't we just say 'Undyne' instead?" he joked.

Alphys's face flushed red instantly. "W-w-what!?" She screeched, "She has absolutely nothing to do with my key word! I've never even spoken to her before anyway! I chose it randomly! I swear!" Sans exchanged looks with Gaster; both were amused. "Oh no, no, no, no, _no—_ " Alphys frowned, poking at Gaster's chest, "You don't get to have that look on your face around me when you're cru—"

Gaster yelled and jumped to cover the yellow monster's mouth before she could finish her sentence. "Okay, I'm sorry! I'm sorry!" He apologised frantically, carefully releasing her once he was convinced she wouldn't keep blabbing. "Let's just…let's just back to the serious matter at hand instead…"

"Pfft. Serious." Naiman scoffed to himself.

"Don't patronise me, Naiman." Gaster frowned at the mechanic before returning his attention to his best friends, "All you've got to tell me is 'void goop' and I'll know you're from the future."

"Void goop?" Alphys repeated as she started cackling hysterically. Sans snickered a bit as well. It was a little funny, despite his pressing concerns.

"Yeah, it's _actually_ random." Gaster teased, "And, like, what does it even mean? Who knows? That's why it's the perfect key phrase!"

"Sexy fish is better!" Alphys challenged.

"Sir, we _really_ should inspect the Core." Naiman insisted, thoroughly annoyed with their antics.

"Just a second." Gaster said, silencing him with a brief hand gesture, "Sans has to give us his key word."

"i want to review the math of the theory behind this experiment." Sans stated, now that he could finally squeeze in a word.

"That's…lengthy." Gaster grimaced.

"I don't think I can remember that." Alphys admitted.

"i'm serious." Sans asserted, and it was a little strange. He was always the jokester. Or, at least, he _used_ to be. "i have a reason to believe there's a crucial error somewhere in there."

If Sans couldn't convince Gaster he was from the future and to stop the experiment, then this was the next best thing. Something went wrong the last time they went through with the experiment and the skeleton was certain he could find proof of it somewhere in their math. After all, if everything was absolutely perfect, then there would have been no reason for their experiment to fail.

"What…really?" Gaster asked disappointedly, "I thought you recovered from your mental breakdown thing."

"there's a mistake in there, there has to be." Sans insisted, determined.

"What's this nonsense?" Naiman grumbled.

"Naiman, don't be rude." Gaster chastised, "But seriously Sans, you can't really want to do that. We've been working on that theory for _years_. Do you know how long it's going to take to review everything?"

"there's a mistake." Sans persisted, and he felt himself growing frustrated. The last thing he wanted was to be dismissed again. They needed to believe him. _Gaster_ needed to believe him. _it's going to kill you. please believe me._

Gaster stared at him for a long time before sighing in defeat. "Fine."

"What!?" Alphys and Naiman shrieked together.

"Sans and I are going to review the theory for any possible mistakes." Gaster declared.

"All of it?" Alphys asked incredulously.

"All of it." He confirmed. "Alphys, you're in charge until we're done. I want you to go inspect the Core with Naiman and address any questions or concerns the crew may have. We are to not be bothered; it'll help us finish faster."

"What about what I was doing?" She asked, glancing at the stack of boxes.

"You can dump the task on someone else if you want." Gaster shrugged, "Or you can do it later, I don't really care."

"This is ridiculous." Naiman objected, "We need your full focus on the final preparations! You'll be wasting everyone's time!"

"And what if there's actually a mistake, Naiman?" Gaster shot back, "What if Sans was right and we stumble upon something that could have resulted with the Core's explosion? I'd rather _spend_ my time appeasing worries and confirming everything is perfectly fine than pushing forward with the slight possibility of a miscalculation nagging me at the back of my mind." He then turned his back to the mechanic, pressing his hand to Sans's back so as to lead him away, "Now if you'll excuse us, we've got a theory to review."

Naiman hissed, glaring at the floor. He muttered something beneath his breath that Sans couldn't quite make out. He thought he might have said something along the lines: "of course, he does whatever his favourite wants", but he couldn't be certain. Sans wasn't even sure what he thought he heard made sense. Regardless, he was just happy he managed to convince Gaster to listen to him in spite of his doubt and the displeasure of others. They would all be grateful once they found the mistake, and so Sans didn't feel particularly bad diverting the Royal Scientist's attention.

They walked into Gaster's office, closing the door and locking it behind them. Gaster then rolled up his sleeves and opened his closet to reveal a dozen boxes overflowing with papers. He sighed and cracked his back before reaching for one. "Alright…" he said, bringing it to his desk, "let's get to work."

OoO

Reviewing their theory behind time travelling had taken tireless hours upon hours. They had gone over the math twice to be certain of not having missed anything. Sans had been as meticulous as possible, taking his time to make sure the equations lead to the proper conclusions. It had been taxing and long. The day had slipped away by the time they finished and Sans could hardly believe neither had found even one little mistake. The math behind the theory and the laws of physics they observed and had studied to conceptualise the machine that would be bringing them back in time, everything, suggested their experiment would succeed.

"this can't be right…" Sans muttered, "there has to be a mistake—"

"Well, there isn't." Gaster yawned, kicking his feet up on his desk. "Are you ready to get back to work now? Not today, obviously—I mean, in general. Like tomorrow or something."

"no, Gaster, there's really a mistake." Sans insisted and began digging through the papers surrounding him. There had to be a miscalculation somewhere. "we must have missed it—"

"Sans," The Royal Scientist interrupted, now visibly exasperated, "I'm not going to look this over a _third_ time with you. Enough is enough. Everything is perfect, our experiment is going to work." He sat up properly and trained his gaze on the small skeleton, "What's going on with you? Why are you so anxious to pull the plug?"

Sans gritted his teeth together, squeezing the papers he clutched in his hands. "time travelling is a terrible idea." He tried, unsure if he would be able to talk reason into the other monster, "we're running so many horrible risks. what if we create a paradox? what if we destroy the fabric of space and time?"

Gaster kept a neutral expression as his eyes inspected Sans for a long moment. He hummed to himself before finally conjuring a reply. "That's not really what concerns you." He concluded.

Sans held in a flinch. He hadn't expected the Royal Scientist to be able to read him so easily. There was another pause during which he lamented what he should do next. It seemed there was no point in telling the truth, but… "what if you died?" he asked quietly, refusing to meet Gaster's gaze. "what if you were erased from existence?"

"Those are improbable scenarios." Gaster replied slowly.

 _It's what happens to you._ Sans thought, glancing up to finally look at his best friend. "i don't want to lose you. could we please just…find another way to break down the barrier?"

"You know I can't do that." Gaster said, "Not after all the years of work that went into this."

The refusal was crushing. It weighed on Sans, had him drop his gaze to the ground and slacken his shoulders. He had failed once again. He really couldn't reason with Gaster like he thought he could. Nothing he said could convince him to stop. Did he just want to die? Was this all inevitable? Was the Groundhog Game just a farce? Did the Dog and Frisk intend to show him that what happened really _had_ to happen? That there was no way around it, no matter how much he wanted there to be?

"Sans?"

The skeleton looked up, feeling tears begin to prickle at his eyes. He barely managed to hold them in. Was there really a point in him being here? Would this really all be for nothing?

"Go home. Rest." Gaster said softly. "Tomorrow, I'm actually going to expect you to help out. I'm sure the others are tired of taking over your tasks."

What was Sans supposed to say now? He had tried telling the truth. He had tried showing the experiment would only lead to disaster. He had tried warning Gaster of his impending death. He had tried but nothing he did worked. No one believed him and Sans wasn't able to prove what he knew to be true. He was probably going to have to suffer a second reset. It was almost as though there was no way around it.

"okay." He uttered quietly and stood.

* * *

You watched Sans trudge out of Gaster's office with a desolated look paving his expression. He seemed so defeated, so hopeless. You wished you could tell him to stay determined. You wished you could hug him too – he really seemed like he needed it right now. It hurt you to see him like this, but there was no other way if it meant saving Gaster. It was what Sans wanted…wasn't it?

"He gets discouraged quite quickly, doesn't he?" The Dog mused.

"He does." You agreed.

"His attempts aren't going over very well either." He added.

"It doesn't matter." You said, "He's learning from his mistakes and he'll do better when he tries again."

"If he wants to." The Dog muttered slyly. You flinched and pinched your lips together in unease. "I mean, look at him go. He's trying so hard not to set his mind on succeeding the first time, but he's failing miserably. It's a testament to how much _you_ exhausted him with your resets."

You glanced at your feet guiltily, the glare of the surrounding abyss barring into your back. You didn't mean to make him so miserable. You didn't mean to hurt anyone. You simply enjoyed reliving the initial encounter of those you held so dearly to your heart. But that hardly mattered, didn't it? You inflicted irreparable damage onto Sans and only now did you begin to consider that it might cost you the bet.

"He's going to be okay." You declared, "Each reset will reinvigorate him because he'll know he's getting closer to a way to saving Gaster."

"That's one possible outcome." The Dog conceded with a short nod, "However, the most likely result is that he'll suffer and that'll make him weaker. Much weaker. Not only will he continuously be watching his best friend die, unlike with Papyrus, he'll actually have been physically trying to stop it from ever happening."

The abyss's glare increased, practically searing into you. You didn't understand why the darkness reacted to you in such a way. Didn't the Dog have control of it? He seemed indifferent to the suffering you had once caused, but maybe it wasn't truly the case? Was He doing this to you purposefully? You glanced back behind you, expecting to see someone or something but finding nothing.

"I guess…there's only one way to find out." You muttered slowly, turning your attention back to Sans.


End file.
